The Outlook blog goes over each of the new security features in detail. One of them is DMARC, which stands for Domain-based Message Authentication, Reporting and Conformance. It's been set up so users can fight off phishing email attacks that seem to come from a real source, such as a email from a bank that is in fact looking to steal personal information. The blog states:

Our DMARC implementation helps protect you by making it easier to visually identify mail from senders as legitimate, and helps keep spam and phishing messages from ever reaching your inbox. If a sender supports DMARC, we put a trusted sender logo next to their email indicating it is legitimate. The effect is cumulative; the more the email sending services that use DMARC, the broader the protection offered against phishing.

The other common phishing scam is when a person is directed to click on what looks like a real web page but is in fact created to take personal information. Websites that use the older SSL certificates for authentication have been known to be compromised. Outlook.com now supports the Extended Validation (EV) certificates. The blog states:

EV certificates are deeply vetted by the Certificate Authority, providing significant assurance that you can trust the sites that use them. These certificates require a minimum of 2048-bit encryption, which is far more secure than what is commonly used with standard SSL.

Microsoft says that in addition to Outlook.com, EV support will be added to SkyDrive in the near future. People who continue to use the older Hotmail.com and Live.com will get the "same level of protection" while they move onto Outlook.com.